title: wzi Gene sequencing, a rapid method for determination of capsular type for Klebsiella strains.
abstract: Pathogens of the genus Klebsiella have been classified into distinct capsular (K) types for nearly a century. K typing of Klebsiella species still has important applications in epidemiology and clinical microbiology, but the serological method has strong practical limitations. Our objective was to evaluate the sequencing of wzi, a gene conserved in all capsular types of Klebsiella pneumoniae that codes for an outer membrane protein involved in capsule attachment to the cell surface, as a simple and rapid method for the prediction of K type. The sequencing of a 447-nucleotide region of wzi distinguished the K-type reference strains with only nine exceptions. A reference wzi sequence database was created by the inclusion of multiple strains representing K types associated with high virulence and multidrug resistance. A collection of 119 prospective clinical isolates of K. pneumoniae were then analyzed in parallel by wzi sequencing and classical K typing. Whereas K typing achieved typeability for 81% and discrimination for 94.4% of the isolates, these figures were 98.1% and 98.3%, respectively, for wzi sequencing. The prediction of K type once the wzi allele was known was 94%. wzi sequencing is a rapid and simple method for the determination of the K types of most K. pneumoniae clinical isolates.
authors.affiliation: Institut Pasteur, Microbial Evolutionary Genomics, Paris, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Brisse
authors.forename: Virginie
authors.initials: V
authors.lastname: Passet
authors.forename: Anita Björk
authors.initials: AB
authors.lastname: Haugaard
authors.forename: Anamaria
authors.initials: A
authors.lastname: Babosan
authors.forename: Najiby
authors.initials: N
authors.lastname: Kassis-Chikhani
authors.forename: Carsten
authors.initials: C
authors.lastname: Struve
authors.forename: Dominique
authors.initials: D
authors.lastname: Decré
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007711:Klebsiella pneumoniae / Q000145:classification* / Q000235:genetics*; D058889:Molecular Typing / Q000379:methods*; D017422:Sequence Analysis, DNA
chemical_list: D001425:Bacterial Outer Membrane Proteins